Tools for HEMS units: A concept for major incident triage by Anders Haug Thomassen

Fig. 1: HEMS units are regularly involved in the management of major incidents that need structuring and standardising – given the multitude of responders (Photographs: Norwegian Air Ambulance Foundation)

Authors: Marius Rehn Norwegian Air Ambulance Foundation Dpt. of Anaesthesia and Intensive Care, Akershus University Hospital,Lørenskog marius.rehn@ norskluftambulanse.no Trond Vigerust Norwegian Air Ambulance Drøbak Jan E. Andersen Norwegian Air Ambulance Foundation Drøbak Andreas J. Krüger Norwegian Air Ambulance Foundation Drøbak & St. Olav University Hospital, Department of Anesthesia and Emergency Medicine, Trondheim, Norway Hans M. Lossius Norwegian Air Ambulance Foundation Drøbak & University of Bergen, Department of Surgical Sciences Bergen, Norway

Tools for HEMS units: a concept for major incident triage HEMS units are regularly involved in the immediate response during major incidents. Efficient management of these incidents involves triage, treatment and transport. HEMS units often operate in several regions and must adapt to local systems for incident management, when national standards are lacking. In the absence of a standardised interdisciplinary major incident management approach, the Norwegian Air Ambulance Foundation developed the Interdisciplinary Emergency Service Cooperation Course (TAS). The TAS-program was established in 1998 and by 2011, approx. 17,000 emergency service professionals had participated in one of more than 600 courses free of charge. The TAS-triage concept has modified the established triage sieve, as slap-wrap reflective triage tags and paediatric triage stretchers have been integrated. Feasibility and accuracy of the TAS-triage concept by the Norwegian Air Ambulance Foundation were evaluated through full-scale bus crash simulations. Learners participated in a self-report survey – as a before-after study – in which triage accuracy as well as time consumption were measured. The modified triage sieve tool was found to be feasible, time-efficient and accurate in allocating priority during simulated bus accidents and may be a candidate for a future national standard for major incident triage.

Major incidents are heterogeneous in nature and their unexpectedness favours an “all-hazards” approach. Since rescue capacity varies within systems, the conditions of a major incident that may be relevant for a rural emergency service, may not apply to a larger urban emergency service (1). Rapid access to advanced major incident management has proven to optimize resource use and improve patient outcome (2). Major incident management traverses geographical and jurisdictional boundaries and involves responders from multiple rescue services. Furthermore, it involves multiple tasks such as leadership, preparation, risk-evaluation, triage, treatment and trans-

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| port. HEMS units are regularly involved in the management of major incidents. Structuring and standardising these initiatives seems essential, given the multitude of responders. The TAS-courses have gradually evolved and the principles for disaster health education – as proposed by the World Association for Disaster and Emergency Medicine – have successively been adapted (3). Major incidents require systems that allow providers to follow their daily pattern of behaviour, the “doctrine of daily routine”. The TAS-concept focuses on training through which participants practise local inter-disciplinary cooperation and simple, field-friendly techniques. Acknowledging that triage is necessary to achieve the greatest good for the most number of people (4), the Norwegian Air Ambulance Foundation (NAAF) developed a concept for major incident triage, based on the established triage sieve and Paediatric Triage Tape (PTT) models (1, 5). The triage Sieve is a major incident primary field triage tool designed to prioritize patients for evacuation in order to provide them with definitive medical care. Based on the assessments of the ability to walk, airway patency, respiratory- and heart rate, the triage sieve assigns four priorities (1): • P1: immediate (red) • P2: urgent (yellow) • P3: delayed (green) • Deceased (white/black) In order to increase field-friendliness, NAAF designed weatherproof action cards (see Figure 2) and slap wrap reflective triage tags (see Figure 3). Furthermore, a tape was designed that presents vital data intervals and that is placed at the side of stretchers to ensure field-friendly access to the paediatric triage algorithm. All children in need of stretchers are categorised as P2, urgent (yellow), but are upgraded to P1, immediate (red) priority, when vital signs lie outside their length-related reference values (6). The study hypothesis was that learners would improve in speed, triage accuracy and self-efficacy after the TAScourse. This article shortly describes the feasibility of a concept for major incident triage and presents the accuracy of the modified triage Sieve in full-scale simulations of major incidents.

Methods TAS-course Local emergency service personnel (healthcare, police, fire and rescue technicians) were taught major incident self-safety, triage, patient evacuation, extrication techniques and cooperation during a two-day course (free of charge). The didactic programme combines theoretical and practical sessions and is tailored to groups of various sizes and professional compositions. A major incident was simulated outdoors using a standardised bus crash scenario, including approximately 20 patients (range 1721) and a real-size bus wreck. Every patient was given an information card with injury descriptions as well as numeric vital signs for triage purposes. Physiological parameters were dynamic to mimic de-compensation and to

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Evacuated clearing station

WALKING?

YES

INJURED?

Evacuated

YES

DELAYED (P3)

DECEASED

BREATHING? YES 10 - 30

BREATHING?

YES

< 10 or > 30

IMMEDIATE (P1)

> 120 < 120

URGENT (P2)

PULSE

visualize the need for re-triage. The patients were equally distributed between the four priorities (all categories had 25% representation). Paediatric patients were simulated with mannequins for ethical reasons. The bus-crash scenario was simulated once at the beginning of the course and once at the end of the course (with formal triage sieve competence/access to TAS-triage action cards, triage tags and paediatric triage stretcher). The didactic program was piloted and refined through 43 TAS-courses prior to the study.

Fig. 2: Modified triage sieve action card: Adult (>140 cm) triage sieve

Study design A self-report survey (before-after study) was combined with an objective quality indicator measurement. Prior to both excercises and based upon informed consent, all participants anonymously answered a written survey. By means of the two questionnaires (that were linked without violating anonymity), self-efficacy and reaction to the training were evaluated. Each question relating to self-efficacy was scored on a 7-point Likert scale with points that ranged from “Did not work” (1) to “Worked excellently” (7). During both exercises, one instructor documented quality indicators such as over- and under-

Fig. 3: Field-friendly slap-wrap reflective triage tags in holster

| 32) before and mean 10 minutes (range 5-21) in the simulation after the course was attended.

Self-efficacy and reaction to training The slap-wrap triage tags were reported to work well, median = 6 (IQR 6-7). The learners found the paediatric triage tape stretcher feasible, median = 5 (IQR 4-6). Self-efficacy before and after the TAS-course is depicted in Table 2.

Discussion

Fig. 4: During a two-day course, local emergency service personnel were taught major incident selfsafety, triage, patient evacuation, extrication techniques and cooperation

triage rates. Triage accuracy was calculated according to allocated priority at the casualty clearing station (first simulation; without TAS-triage) and according to TAS-triage tags (last simulation; with TAS-triage). The instructors also measured quality indicator, that is the time from “scene secured” to “all patients triaged” (in minutes).

Results Descriptive A total of 110 emergency service professionals attended one of the four courses and 93 learners (85%) answered the questionnaires. Among the study-participants, 28% worked in healthcare (nurse, ambulance, other), 51% were fire fighters, 14% of the participants were police officers and 7% had “other” backgrounds. The mean participant age was 39 years (range 20-62), 84% were men and the median working experience was eight years (range 0-34).

Triage accuracy and time expenditure

Table 1: Triage accuracy with and without the use of TAS-triage

Out of the total number of learners, 48% confirmed that a system for major incident triage existed in their service, whereas 27% had access to triage tagging equipment. Triage accuracy with and without the use of TAS-triage is depicted in Table 1. Time from “scene secured” to all patients were triaged was mean 22 minutes (range 15-

Emergency service personnel reported a significantly increased self-efficacy in major incident triage after being taught the TAS-concept (Table 2). The modified triage sieve and paediatric triage tape stretchers were time efficient and accurate (Table 1) in allocating patient priority in simulated major incidents. It was found that the TASconcept for major incident triage is feasible for Norwegian emergency service personnel. The TAS-concept emphasizes interdisciplinary cooperation and all emergency service professionals (healthcare, police and fire fighters) are taught triage techniques. In a study of British police officers attending a tactical medicine course, Kilner et al. found that learners were able to make accurate triage decisions after being provided triage sieve decision-making material (7). Major incident triage remains a neglected field for scientific inquiry (8), and determining effectiveness of triage tools has been identified as a critical area for research (9). The optimal triage algorithm is characterized by simplicity, time efficiency, predictive validity, reliability and accuracy to minimize mistriage (10). In a review of published experience with terrorist bombings, Frykberg and Tepas found a mean overtriage rate of 59%. They also identified a linear relationship between overtriage rate and critical mortality (11). There are several limitations to this study, for example unrealistically high triage accuracy. In a chaotic environment, accurate measurement of vital data such as respiratory and heart rate may not be achieved. Optimally, the concept for major incident triage should not have been evaluated in simulations, as they can only serve as approximates of complex real incidents. Until real-incident experience with the TAS-concept is objectively measured, models have to be kept feasible, time efficient and accurate in full-scale simulations. Modifications of the TASconcept compared to Major Incident Medical Management and Support (MIMMS) triage sieve include: •

Triage accuracy with and without the use of TAS-triage Without TAS-triage

With TAS-triage

Course

Overtriage

Undertriage

Overtriage

Undertriage

3/20 (15,0%)

1/20 (5,0%)

0/20 (0%)

3/20 (15,0%)

0/20 (0%)

2/17 (11,8%)

0/17 (0%)

1/17 (5,9%)

3/17 (17,6%)

0/21 (0%)

Total

9/74 (12,2%)

0/78 (0%)

Note: Triage accuracy = mistriage/total patients (n) *) Simulation was conducted without paediatric mannequins/patients, but with access to Paediatric Triage Tape Stretcher

• •

Omission of capillary refill, as decreased temperature and dark conditions significantly impairs the field assessment of capillary refill time (12,13) Category “dead” was renamed to “lifeless”, as jurisdictional restrictions apply to defining death in Norway MIMMS paper tags were replaced with slapwrap reflective triage tags. Paper tags are likely to perish in the sub-arctic Norwegian climate (14, 15) and they deviate from familiar routines when stress suggests simple and field-friendly solutions.

Major incident triage is dynamic and patients are repeatedly re-triaged along the evacuation chain and through

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| the receiving hospital until definitive treatment is received. HEMS units are regularly involved in the management of major incidents in many regions. Accordingly, they also benefit from efficient standardized multidisciplinary major incident triage. In Norway, a train accident near Aasta killed 19 people whereas 67 passengers survived. Approximately 600 personnel from 11 different services participated in the initial management of this major incident (16). Further, during a major aircraft incident in UK, the simultaneous use of several different triage-labelling systems contributed to confusion (17). A triage concept with uniform instructions and standardized triage tagging would alleviate on-scene confusion and national standards has been called for both in the US and Australia (10,18). In Norway, the lack of a standard major incident

Self-efficacy before and after the TAS-course question

before course (n)

mean

95% CI

(n)

mean

95% CI

“How did triage work?”

4,9

4,6–5,1

5,9*

5,7–6,1

“How did interdisciplinary cooperation of triage work?”

4,9

4,7–5,2

5,8*

5,6–6,0

“How did triage-tagging work?”

3,8

3,4–4,3

6,0*

5,8–6,1

triage concept that is nationally accepted, reliable and validated remains a gap in our major incident preparedness (19).

Conclusions References: 1. Advanced Life Support Group (2002) Major incident medical management and support, the practical approach at the scene. 2nd edition BMJ Publishing Group, Plymouth 2. Aylwin CJ, Konig TC, Brennan NW et al. (2006) Reduction in critical mortality in urban mass casualty incidents: analysis of triage, surge, and resource use after the London bombings on July 7, 2005. Lancet 368: 2219-2225. 3. Seynaeve G, Archer F, Fisher J, Lueger-Schuster B, et al. (2004) International standards and guidelines on education and training for the multi-disciplinary health response to major events that threaten the health status of a community. Prehosp Disaster Med 19: 17-30 4. Pesik N, Keim ME, Iserson KV (2001) Terrorism and the ethics of emergency medical care. Ann Emerg Med 37: 642-646 5. Hodgetts T, Hall J, Maconochie I, Smart C (1998) Paediatric triage tape. Pre-Hospital Immediate Care 2: 155-159 6. Rehn M, Vigerust T, Kruger AJ, Andersen JE (2010) Paediatric vital sign tape on stretchers: a field-friendly triage tool? Emerg Med J 27: 412 7. Kilner T, Hall FJ (2005) Triage decisions of United Kingdom police firearms officers using a multiple-casualty scenario paper exercise. Prehosp Disaster Med 20: 40-46 8. Jenkins JL, McCarthy ML, Sauer LM ez al. (2008) Mass-casualty triage: time for an evidence-based approach. Prehospital Disaster Med 23: 3-8 9. Rothman RE, Hsu EB, Kahn CA, Kelen GD (2006) Research priorities for surge capacity. Acad Emerg Med 13: 1160-1168 10. Armstrong JH, Frykberg ER, Burris DG (2008) Toward a national standard in primary mass casualty triage. Disaster Med Public Health Prep 2 (Suppl. 1): 8-10 11. Frykberg ER, Tepas JJ (1988) Terrorist bombings. Lessons learned from Belfast to Beirut. Ann Surg 208: 569-576 12. Gorelick MH, Shaw KN, Baker MD (1993) Effect of ambient temperature on capillary refill in healthy children. Pediatrics 92: 699-702 13. Brown LH, Prasad NH, Whitley TW (1994) Adverse lighting condition effects on the assessment of capillary refill. Am J Emerg Med 12: 46-47 14. Knotts KE, Etengoff S, Barber K, Golden IJ (2006) Casualty collection in masscasualty incidents: a better method for finding proverbial needles in a haystack. Prehospital Disaster Med 21: 459-464

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after course

Table 2: Self-efficacy before and after the TAS-course (Note: Each question was scored on a 7-point Likert scale with points ranging from ”Did not work” (1) to “Worked excellently” (7). *) p < 0,001)

Major incident triage skills can be effectively taught to multi-disciplinary emergency service professionals using a combination of lectures and practical simulations in a two-day course. The modified triage sieve tool discussed here provides acceptable accuracy in allocating priority during simulated major incidents and may serve as a candidate for a future national standard for major incident triage.

15. Chan TC, Killeen J, Griswold W, Lenert L (2004) Information technology and emergency medical care during disasters. Acad Emerg Med 11: 1229-1236 16. Norges Offentlige Utredninger (2000): Aasta-accident, 4th of January. Book Aastaaccident, 4th of January, vol. NOU City, Oslo: 30 17. Staff of the accident and emergency departments of Derbyshire Royal Infirmary, Leicester Royal Infirmary, and Queen’s Medical Centre, Nottingham (1989) Coping with the early stages of the M1 disaster: at the scene and on arrival at hospital. Bmj 298: 651-654 18. Nocera A, Garner A (1999) Australian disaster triage: a colour maze in the Tower of Babel. Aust N Z J Surg 69: 598-602 19. Rehn M, Lossius HM (2010) Katastrofetriage-behov for en nasjonal standard (In Norwegian). Tidsskr Nor Laegeforen 130: 2112-3

Fig. 5: Sub-arctic climate requires field-friendly triage solutions

An earlier version of this article appeared in BMC Emergency Medicine as: “A concept for major incident triage: full-scaled simulation feasibility study”. Rehn et al. (2010) BMC Emergency Medicine 10: 17. Reprinted with permission of the authors.